1. Field of the Invention
The present invention relates to an endoscope apparatus which can be inserted with improved operability.
2. Related Art Statement
Conventionally, there have widely been used endoscopes (scopes or fiber scopes) of which elongate insert sections can be inserted into the body cavities for diagnosing or examining internal organs of a living body and the like. In addition to the medical field, endoscopes have been used in the engineering field as well to observe or check objects such as interiors of pipes or machines of boilers, machinery, chemical plants, etc.
Further, various types of endoscopes using solid imaging devices, e.g., charge coupled devices (CCD's), as imaging means have also been practiced.
The endoscope comprises, for example, an elongate and flexible insert section, a larger-diameter grip section continuously provided at the rear end of the insert section, and so fourth. The insert section comprises a hard distal end component, a bendable portion continuously provided at the rear end of the distal end component and capable of bending upwards, downwards, rightwards and leftwards, for example, and a flexible pipe portion continuously provided at the rear end of the bendable portion.
The bendable portion has an outer covering member made of a bendable material such as rubber.
However, use of the bendable rubber is problematic in that when it strongly contacts an object to be examined, e.g., a wall of the body cavity, the contact resistance is increased, which makes it hard to further insert the insert section.
Meanwhile, Japanese Patent Laid-Open No. 229218/1989 discloses a technique which utilizes a fluid intermittently supplied to the insert section, for lifting a part of the insert section in an intermittent manner so as to vibrate the insert section. With this technique, however, since the fluid is jetted against the object to be examined and the resulting counteraction is utilized to vibrate the insert section, the object is subjected to a large impact and hence a problem arises when applied to medical endoscopes, in particular.